California Amateurs Claim New World Distance Record on 3.7 mm Band

Mountain-topping radio amateurs in California are claiming a new world distance record on the 77 to 81 GHz band — also known as “E band” — a band many hams likely are unaware of and whose future is unclear. The claimed record was set June 13 between Robert Johnson, KF6KVG, on a peak just east of San Jose and Goran Popovic, AD6IW, in Kings Canyon National Park to the east-southeast.

“We achieved a distance of 252.49 km from Mt Hamilton (CM97di) to Kings Canyon National Park (DM06ms),” Goran, AD6IW, announced on the 50 MHz & Up Group reflector. “We made two-way contact on FM and SSB with strong signals at both ends.”

KF6KVG used a 1-foot dish, and AD6IW a 2-foot dish. Both employed dielectric resonator oscillator-locked frequency control for extreme stability. The current E band record is 228 km, set in Germany between Philipp Prinz, DL2AM, and Alexander Wetzel, DL2GWZ.

According to ARRL CEO David Sumner, K1ZZ, this amateur band was first allocated internationally in 1979 as 75.5-81 GHz, with 75.5-76 GHz primary and the remainder secondary. When allocations below 76 GHz were realigned at WRC 2000, 75.5-76 GHz was deleted, 81-81.5 GHz was added as secondary, and the primary allocation was shifted to 77.5-78 GHz although only 77-81 GHz is available currently to amateurs in the US. Sumner says the band 77.5-78 GHz is under consideration at WRC 2015 for an allocation for automotive short-range radar, leaving the fate of the amateur primary allocation uncertain.